Straightening vehicle frames or bodies



March 27, 1962 A. H LUEDICKE, JR, ET AL 3,026,925

STRAIGHTENING VEHICLE FRAMES OR BODIES Original Filed May 20, 1959 2Sheets-Sheet 1 IN VEN TOR.

3,026,925 STRAIGHTENING VEHICLE FRAMES OR BODIES Alex H. Luedicke, Jr.,Bellevue, Wash., and William R. Chapman, Waukesha, Wis., assignors toApplied Power Industries, Inc., a corporation of Wisconsin Originalapplication May 20, 1959, Ser. No. 814,428, now Patent No. 2,998,837,dated Sept. 5, 1961. Divided and this application Mar. 8, 1961, Ser. No.94,397

5 Claims. (Cl. 153-32) The present invention relates generally toimprovements in the art of straightening structural elements, andrelates more particularly to improvements in the construction andoperation of vehicle frame and/r body straighteners and a method ofstraightening frames.

This application is a divisional application of our copending UnitedStates application Serial No. 814,428, filed May 20, 1959.

In vehicle frame straightening work, the repairmen are generallyconfronted with five basic types of frame damage, namely, verticaldistortion or sag, side sway or lateral distortion, twist, siderailswhich are longitudinally displaced or out of square, and kick-up orsharp bends in the siderails. While several straightening tools havebeen heretofore proposed which are adapted to correct one or more ofsuch types of damage, no single tool thus far commercially available iscapable of effectively repairing all five of the basic types of damage.

Furthermore, it is also essential that frame straightening apparatus forwork on damaged vehicles be of a portable nature and readily adjustablefor convenience in properly manipulating the tool and applying the sameto the damaged frame for most effectively performing the necessaryrestoring work. While some of the presently commercially available framestraighteners are portable or semi-portable, they do not possess thedesired degree of adjustability and flexibility of application.

In addition, the frame straightening devices heretofore proposed havefor the most part been unduly bulky and difficult to store andmanipulate, and some of these devices require the use of expensivelifting equipment, special costly adapters, and considerable manpower intheir application and use.

It is therefore an important object of the present invention to providean improved vehicle frame and/ or unitized body straightening device andmethod which obviates all of the above-mentioned disadvantages andobjections to prior frame straightening devices especially in thecorrect-ion of twist damage.

Still another object of our invention is to provide an improved vehicleframe straightening device which is extremely portable, relativelycompact, readily adjustable, and highly flexible in its adaptations, andwhich is capable of manipulation and use by a single operator.

An additional important object-of the present invention is to provide animproved method of and apparatus for removing or correcting twist damageto vehicle frames and unitized bodies.

These and other objects and advantages of the invention will becomeapparent from the following detailed description.

A clear conception of the several features constituting the presentimprovement and of the mode of applying and utilizing the apparatus, aswell as the method, in the correction of twist damage, may be had byreferring to the drawings accompanying and forming a part of thisspecification wherein like reference characters designate the same orsimilar parts in the various views.

FIGJ is a fragmentary side view of a typical straightening deviceembodying a twist correction beam and showing the same in assembledcondition for storage;

nited States atent Patented Mar. 27, 19612 FIG. 2 is a fragmentary sideview showing the improved device in operative position and applied to atypical, twisted vehicle frame; and

FIG. 3 is a fragmentary top view of the device as applied to the twistedframe of FIG. 2.

While the present invention has been shown and described herein as beingespecially applicable in straightening vehicle frames of a particulartype having one form of damage, it should be understood that the use ofthe improved device is not thereby unnecessarily restricted since it isequally adaptable to the correction of any known types of frames havingone or more forms of damage, and the device is also well adapted to therepair of unit bodies which are difiicult to manipulate with prior framestraighteners. It is also contemplated that the broadest possibleinterpretation shall be given to various descriptive terms used herein,and the use of the term frame throughout this specification and theappended claims is intended to apply either to a structural frame memberas such or to that part of a unitized body corresponding to the frame.

Referring to the drawings and particularly FIG. 1, the typical improvedframe straightening device shown therein as embodying a twist correctionbeam comprises, in general, a tubular main beam 10, a beam extension 11adapted to telescope within one end of the beam 10 and extensible tovarious positions of adjustment, a pivot arm 12 secured to the other endof the main beam 10, a hook 13 slidable longitudinally to differentpositions of adjustment along the pivot arm 12, a hydraulic power sotuator 14 secured between the beam 10 and pivot arm 12, a post 15secured to the exposed end of the extensible beam 11 and adapted to beswung from an inactive horizontal position to vertical position, and atwist correcting beam 16 detachably secured to the main beam 10 as bymeans of a 'U-bolt 17 and clamp 18.

The main beam 10 is shown as being supported by a pair of floor-engagingwheels 20 while the extensible member is provided with a floor-engagingcaster 21 to thus render the device readily portable and capable ofproper positioning by a single operator. To accommodate frames ofdifferent types and sizes and to permit adjustment for the performanceof various types of work, the telescopic beam extension may be readilyextended to desired positions, and upon adjustment, a lock pin 22 may beinserted through alined holes 23, '24 in the beams 10, 11 respectivelyto maintain the beams in extended condition.

The post 15 is secured within a cut-out portion of the extensible beam11 by means of a pivot pin 25 to permit the same to be readily swungfrom horizontal inactive position as shown in FIG. 1 to a verticalposition, and when in vertical position, the post 15 bears against atransverse edge 26 of the upper run of the beam 11 which is reinforcedby a bearing plate 27 secured to the beam as by welding or the like.

The pivot arm 12 is secured to the beam 10 by means of a pair of lowerflange plates 31 forming a bifurcated member extending on opposite sidesof the beam and secured to the beam or to suitable side plates 32thereof by a pivot pin 33 to permit swinging movement of the arm 12. Thepower actuator 14 may be in the nature of a fluid motor, the head orcylinder end of which is pivotally attached to a bracket or upstandingflange 34 on the beam 10 and the piston or plunger 35 of which ispivotally attached to a bracket or flange 36 on the arm 12. The motor orpower actuator 14 is of conventional type, either single or doubleacting, and the cylinder thereof is connected by a fluid conduit to asuitable pump for furnishing pressure fluid thereto to extend the piston35 and thus swing the arm 12. The hook 13 is swingably carried by astrap 37 slidably embracing the arm 12, the strap 37 having suitableslide shoes 38 secured thereto and provided with set screws 39 forsecuring the hook assembly in any desired position of adjustment alongthe arm 12.

The twist correcting beam 16 may be conveniently secured to the mainbeam in approximately longitudinal alignment therewith by means of theU-bolt 17 and clamping bracket 18 when the device is stored or inactive.When the device is used for correcting sag, side sway, longitudinalsiderail displacement, or sharp siderail bends, as described in detailin our co-pending application, the beam 16 may be readily removed in anobvious manner by merely dismantling the bolt 17 and clamp 18. However,when it is desired to correct a frame which is twisted,

the bolt 17 i IOOSCHCd HIEfiThEbEBHIW tive to the beam 10 to provide anX-shaped too viewed from above, as shown in FIGS. 6 and 7 and ashereinafter more fully described, the bolt 17 and clamp 18 then againbeing tightened.

In straightening damaged vehicle frames, the main idea is to reverse theblow that caused the damage in the first instance so that the metalreturns to its normal shape. It is therefore necessary to firstdetermine the type of damage requiring correction, and this is done withthe aid of commercially available frame gages and dimension charts.After the type of damage has been determined, the improved framestraightener should be applied to the damaged frame so as to pull thebent parts under applied pressure along substantially the same line ofimpact or initial bending force until the frame is restored to itsoriginal position. If several types of damage have been caused andrequire correction, these should be repaired one at a time, and it isgenerally best to start with repairs that pull the damaged parts.

Referring now to FIGS. 2 and 3, the improved frame straightening deviceis shown as applied to a typical twisted frame generally of the box orladder type which comprises a pair of siderails 41, 42 joined near theiropposite ends by transverse rails 43, 44 and at their medial portions bycross-rails 45, 46. In this case wherein the frame has been twisted sothat the front and rear ends of the siderails 41, 42 are out ofhorizontal alignment, the method employed for correcting the damage isas follows. The beam 10 is first positioned diagonally beneath the frameto extend under the low points of the siderails 41, 42, and the twistbeam 16 is swung about the main beam 10 to form an X-shaped supportingstructure with the beam 16 also extending diagonally of the frame andunder the high points of the siderails 41, 42.

After clamping the beams 10, 16 firmly together as by means of theU-bolt 17 and clamp 18, a pair of force applying devices such assuitable hydraulic hand jacks 47, 48 are placed between the main beam 10and the two low points of the frame siderails 41, 42, and the oppositeends of the twist beam 16 are chained to the high points of the framesiderails 41, 42 as at 49, 50. Then, upon application of pressure to thelow points of the frame by means of the jacks 47, 48, the low pointswill be raised and the high points of the frame will be simultaneouslypulled or held down by the chains 49, 50 until the frame is twisted backinto proper alignment, the correction twisting operation being just thereverse of the force which caused the damage initially.

From the drawing and the foregoing description, it is apparent that therestorative operation is accomplished without the application of torqueto the damaged members such as inherently occurs when the members arefirmly clamped in a common plane in the straightening tool whilerestorative force is applied. In other words, the jacks 47, 4S and thechains 49, 50 permit lateral movement of the respective frame portionssince these pressure applying elements are not rigidly clamped to therespective beams and frame members, and also by its very nature, theX-shaped work support permits relav n secured to tive movement of thebeams during the restorative pressure application due to the fact thatthey are crossed with the upper beam having but a single bearing pointat a medial portion thereof.

It should be understood that it is not desired to limit this inventionto the exact details of construction of the improved device or to theprecise steps of the frame cor-- rection method herein shown anddescribed, since various modifications within the scope of the appendedclaims will occur to persons skilled in the art to which this inventionpertains, and the same procedure herein described may be followed in thecorrection of twist damage to a unitized body.

We claim:

1. A vehicle frame straightening device comprising, a horizontal mainbeam, an auxiliary beam supported on a medial portion of said main beamfor lative thereto in a horizontal plane 10 provide an X-shape I o g incorrecting twist damage to a generally re a frame having diametricallyopposed high and low points to be restored, said X-shaped work supportbeing positionable under said frame with the ends of said beams locatedunder the high and low points thereof, means interposed between andcoacting with the ends of one of said beams and the adjacent lowportions of the damaged frame for applying upward pressure to said lowframe portions, and means secured between the ends of the other of saidbeams and the adjacent high portions of the damaged frame for resistingupward movement of said high frame portions during said pressureapplication to said low frame portions whereby the low and high pointsof said frame are thus restored said beams being relatively movableduring said pressure application.

2. A vehicle frame straightening device comprising, a horizontal mainbeam, an auxiliary beam supported on and secured to a medial portion ofsaid main beam for swinging movement relative thereto in a horizontalplane to provide an X-shaped work support for use in correcting twistdamage to a generally rectangular vehicle frame having diametricallyopposed high and low points to be restored, said X-shaped work supportbeing positionable under said frame with the ends of said beams locatedunder the high and low points thereof, means interposed between andcoacting with the ends of said main beam and the adjacent low portionsof the damaged frame for applying upward pressure to said low frameportions while permitting lateral movement of said frame portions, andmeans secured between the ends of said auxiliary beam and the adjacenthigh portions of the damaged frame for resisting upward movement of saidhigh frame portions during said pressure application to said low frameportions while permitting lateral movement of said frame portionswhereby the low and high points of said frame are thus restored, saidbeams being relatively movable during said pressure application.

3. A vehicle frame straightening device comprising, a horizontal mainbeam, an auxiliary beam supported on and secured to a medial portion ofsaid main beam for swinging movement relative thereto in a horizontalplane to provide an X-shaped Work support for use in correcting twistdamage to a generally rectangular vehicle frame having diametricallyopposed high and low points to be restored, said X-shaped work supportbeing positionable under said frame with the ends of said beams locatedunder the high and low points thereof, a jack interposed between andcoacting with each end of said main beam and the adjacent low portion ofthe damaged frame for applying upward pressure to said low frameportions, and a flexible connecting element of fixed length securedbetween each end of said auxiliary beam and the adjacent high portion ofthe damaged frame for resisting upward movement of said high frameportions during said pressure application to said low frame portionswhereby the low and high points of said frame are thus restored, saidbeams being relatively movable during said pressure application.

4. The method of correcting a twisted generally rectangular vehicleframe having diametrically opposed high points and diametrically opposedlow points to be re stored, which comprises, providing a pair ofmedially crossed horizontal beams below said frame with the ends of saidbeams located in proximity to the low and high points of said frame, andthereafter simultaneously applying pressure in vertical planes betweenthe ends of said beams and the adjacent low and high points of saidframe respectively in opposite directions while permitting relativemovement of the beams with respect to each other until the twist hasbeen removed from said frame and the low and high points restored.

5. The method of correcting a twisted generally rectangular vehicleframe having diametrically opposed high points and diametrically opposedlow points to be restored, which comprises, providing a pair of mediallycrossed horizontal beams below said frame with the ends of the lowermostbeam located in proximity to and beneath the low points of said frameand with the ends of the uppermost of said beams being located inproximity to and beneath the high points of said frame, and thereafterapplying restoring pressure upwardly from the ends of the lowermost beamagainst the adjacent low points of said frame while simultaneouslyrestraining movement between the ends of the uppermost beam and theadjacent high points of said frame to thereby restore the high and lowpoints of said frame, said beams being relatively movable during saidpressure application.

References Cited in the file of this patent UNITED STATES PATENTS

